Treatment and outcomes of first troponin-negative non-ST-segment elevation myocardial infarction.
Little is known about non-ST-segment elevation myocardial infarction (MI) in patients with an initial negative troponin finding. The aim of this study was to determine in post hoc analysis of a large regional medical center presenting clinical characteristics, treatment differences, and in-hospital and 6-month outcomes of first troponin-negative MI (FTNMI). In this study, 659 of 1,855 consecutive patients with non-ST-segment elevation MI (35.5%) were classified as having FTNMI. In-hospital cardiac catheterization rates were similar between the 2 groups (70.1% vs 71.5%, p = 0.53) In hospital, patients with FTNMI were less likely to receive statins (48.9% vs 59.9%, p <0.001). On discharge, patients with FTNMI were less likely to be on clopidogrel (53.1% vs 59.0%, p = 0.019) and statins (67.7% vs 75.2%, p <0.001). At 6-month follow-up, patients with FTNMI were less likely to be on clopidogrel (43.5% vs 55.2%, p = 0.01) In-hospital recurrent ischemia was 2 times as common in FTNMI (20.1% vs 11.5%, p <0.001). There were no differences, however, in congestive heart failure, cardiogenic shock, cardiac arrest, stroke, or death in hospital. At 6 months, patients with FTNMI were 2 times as likely to have had recurrent MI (12.0% vs 6.6%, p <0.001). Combined end points of death at 6 months, MI, stroke, and rehospitalization were higher for FTNMI (47.7% vs 40.9%, p = 0.017); however, this was due to higher rates of recurrent MI. In conclusion, patients with FTNMI received less aggressive pharmacotherapy and were 2 times as likely to have recurrent MI at 6 months. FTNMI is common and represents a clinical entity that should be treated more aggressively.